Container seaming assembly

ABSTRACT

Described is a seaming machine for use with a container ( 22 ) and an end closure ( 28 ). The machine includes a seaming head ( 62 ) with multiple shaft assemblies ( 100 ) and a lifter table ( 60 ) located below the seaming head ( 62 ) and including multiple container stations. During use, the lifter table ( 60 ) and seaming head ( 62 ) rotate in unison about the centerline of a spindle ( 64 ). A single shaft assembly ( 100 ) is provided at each station to perform a two-step seaming operation on its corresponding container ( 22 ). In one embodiment, a seaming cam ( 66 ) is located above the seaming head ( 62 ) for moving first and second cam followers ( 116 ), ( 118 ) in the shaft assembly ( 100 ). In another embodiment, the cam followers ( 116 ) and ( 118 ) have a master/slave relationship dependent on which step of the seaming operation is being conducted. In another embodiment, a single piece plate ( 122 ) is used in a cover feed assembly ( 120 ) and provides end closures ( 28 ) to a make-up point ( 30 ).

FIELD OF THE INVENTION

[0001] The present invention relates to an apparatus and process foraffixing a closure to a receptacle, and more particularly, to a workfeeding process wherein either the end closure or the open toppedcontainer is transported or conveyed to an assembly station and furtherto a seaming process including curling overlapping portions of the endclosure and the open ended container into a toroidal bead that liesadjacent the upstanding wall portion of the said container to therebyform an air tight joint.

BACKGROUND OF THE INVENTION

[0002] Container seaming machines have been in use in the industry formany years. Referring to FIGS. 1 and 2, a typical container closureoperation consists of an infeed conveyor 20 that feeds a constant supplyof evenly-spaced, open containers 22 (e.g., metal cans) to a seamingmachine 24. Just prior to reaching the seaming machine 24, a cover feedassembly 26 places an end closure 28 over the container opening at aposition referred to herein as the “make-up point” 30. The cover feedassembly 26 includes a rotating cover feed turret 32 that moves the endclosures 28 along a predefined path. As shown in FIG. 15, the cover feedassembly 26 is formed from a number of separate parts including dualguide sections 34, 38 mounted on the underside of a machine plate 36 andsecured with several small bolts (not shown). The end closures 28 arefed from a cover magazine 46 at a predefined rate.

[0003] The container 22 has a small outwardly extending flange 48 aboutits upper opening. The end closure 28 has a similar flange 50, called“curl”. See FIGS. 17 and 15. After the container 22 receives an endclosure 28, the combination enters the seaming machine 24 where one ormore shaft assemblies 52 (see FIG. 2) fold the flanges 48 and 50 to forman air tight seam. Referring back to FIG. 1, a discharge turret 54 movesthe sealed containers along a discharge conveyor 56 for furtherprocessing.

[0004] In more detail and referring to FIG. 2, the seaming machine 24includes a lifter table 60 and a seaming head 62 connected to the table60 via various supports (not shown). Both the lifter table 60 andseaming head 62 are rotatably connected to a central spindle 64 and arearranged to so rotate in unison at a predefined rate. An upper seamingcam 66 is provided above the seaming head 62, though, the cam 66 doesnot rotate (or at least not at the same speed as the head 62 and table60). The lifter table 60 has multiple stations 68 that each support anindividual container 22. In some embodiments, these stations include“lifters” 70 that physically lift the container 22 upward during theseaming process.

[0005] The seaming head 62 includes multiple shaft assemblies 52outwardly spaced about the seaming cam 66. In FIG. 2, a single shaftassembly is shown for clarity of illustration only. In known machines,there may be anywhere from 1 to 18 shaft assemblies 52 spaced about thehead 62. The shaft assemblies 52 provide the components necessary toform a folded seam between a container 22 and its corresponding lid 28.In one embodiment, the shaft assemblies each include an upright shaft 70that transmits a rotary motion to a pair of rollers 72, 74 via a supportblock 76. The head assembly also includes multiple chucks 80, one ateach container station 68.

[0006] Still referring to FIG. 2, during the closure process, anunjoined container 22 and end closure 28 are placed at a station 68where they are held between a lifter 70 and a chuck 80. Becauseconventional lids 28 include concentric rings that surround slightlysunken circular areas, the chuck contacts the upper surface of the lid,supporting the chuck wall portion of the lid and providing as such ananvil to perform the seaming operation.

[0007] As stated above, the seaming head and lifter table are rotatingabout the centerline of the spindle 64 during the seaming process. Thisallows a constant flow of containers through the seaming machine withouthaving to stop the assembly to load and unload the open and sealedcontainers, respectively. In addition, each container 22 is rotatingabout its own central axis as well. To close the joint, the rollers 72,74 of the shaft assembly press the combined flanges 48, 50 against thechuck 80, causing them to deform into a desired shape. The rollers 72,74 have profiled grooves at their outer circumference that bend theflanges in a specific manner, thus ensuring a perfect seam.

[0008] Referring to FIG. 3, prior art shaft assembly 52 includes anupright shaft 70 that is located between adjacent container stations.First and second rollers, 72 and 74, respectively, are connected to theshaft 70 via block 76. The first roller 72 is sized and shaped toeffectuate an initial partial curling of a downstream container 82. Thesecond roller 74 is sized and shaped to effectuate a final curling of anupstream container 84. Thus, the shaft assembly operates on two separatecontainers. The rollers 72 and 74 act on the containers from thestations located to each side of the shaft. Stated differently, a singlecontainer is sealed using two separate shaft assemblies. In anotherembodiment of a shaft assembly (not shown), a single shaft is used witha single roller, with two such shaft assemblies being provided for eachstation.

[0009] The rollers 72 and 74 accomplish their tasks by being pressedagainst the flanges while the container 22 is rotated about itslongitudinally central axis. The position of the block 76 determineswhich roller will be engaged with a container. The block 76 is connectedto the lower end of the shaft 70. Rotary motion is transmitted to theblock 76 via first and second cam followers 86 and 88 that are locatedat the upper end of the shaft 70. See FIG. 2. The cam followers 86 and88 follow the contours of the seaming cam 66 as the seaming head 62 andlifter table 60 rotate relative to the seaming cam 66. The first camfollower 86 controls the position of the first roller 72. The second camfollower 88 controls the position of the second roller 74.

[0010] The above arrangements, while adequate, have a number ofdisadvantages. The manufacturer must provide machines that are capableof having varying numbers of stations. Each change in the number ofstations will require a separate, redesigned shaft assembly to adjustthe roller arm length and roller pitch. Similarly, it is difficult andtime-consuming for the customer to change the machine setup in thisregard. In addition, the cover feed assembly is difficult to install.When changing from one end closure size to another, the entire assemblymust be reconfigured and the three part cover guides precisely reset.This is time consuming and often requires special skills, tools, andknowledge.

SUMMARY OF THE INVENTION

[0011] In accordance with teachings of the present invention, a seamingmachine is described for forming an air tight joint between a containerand an end closure. The machine includes a seaming head with multipleshaft assemblies and a lifter table located below the seaming head andincluding multiple corresponding container stations. During use, thelifter table and seaming head rotate in unison about a central spindle,thereby moving a stream of containers through the seaming machine. Asingle shaft assembly is provided at each station to perform a two-stepseaming operation on its corresponding container. In preferredembodiments, the shaft assembly includes first and second rollers.

[0012] In accordance with other aspects of this invention, in oneembodiment, a seaming cam is mounted above a seaming head. The seaminghead and lifter table rotate relative to the seaming cam during use. Theshaft assembly includes first and second cam followers arranged tofollow the contour of the seaming cam as the lifter table and seaminghead rotate. The motion of the first and second cam followers providerotary input to the rollers to accomplish the two-step seamingoperation.

[0013] In accordance with further aspects of this invention, a first camfollower acts as a master cam follower that positions the first rollerto accomplish the first seaming step, the second cam follower being aslave to the first cam follower during the first seaming step. Thesecond cam follower acts as a master cam follower that positions thesecond roller to accomplish the second seaming step, while the first camfollower is a slave to the second cam follower during the second seamingstep.

[0014] In accordance with other aspects of this invention, the shaftassembly includes an upright shaft having upper and lower ends. A blockis attached to the shaft lower end. The first and second rollers arerotatably connected to opposite ends of the block about upright axes.The middle region of the block is connected to the lower end of theupright shaft and can rotate with this shaft about the centerline ofthat shaft. In one embodiment, the block is fixed relative to the shaftduring use.

[0015] In accordance with further aspects of this invention, animprovement to a seaming process for affixing an end closure to acontainer opening is described. The container is located at a processingstation in a container closing machine. The improvement includes using ashaft assembly adjacent to each processing station to perform a seamingoperation on a single container during use. The shaft assembly includesfirst and second rollers. The first roller performs a first seaming stepresulting in partial closure of the joint, and the second rollerperforms a second seaming step resulting in final forming of the joint.

[0016] In accordance with other aspects of this invention, a cover feedassembly is described for use in providing end closures to a seamingmachine. The assembly includes a unitary plate having a lower surface, ashallow channel in the lower surface for holding end closures, andinwardly-extending flanges bounding the side walls of the channel. Inone embodiment, the channel is formed in the unitary plate by beingmachined out of a solid material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The foregoing aspects and many of the attendant advantages ofthis invention will become more readily appreciated by reference to thefollowing detailed description, when taken in conjunction with theaccompanying drawings, wherein:

[0018]FIG. 1 is a schematic plan view diagram of a prior art seamingprocess showing the general flow of filled containers through a seamingmachine;

[0019]FIG. 2 is a schematic side view diagram of a prior art seamingmachine, though showing only a single seaming stations for illustrativepurposes;

[0020]FIG. 3 is a schematic plan view diagram of a prior art shaftassembly performing a seaming operation on first and second containers;

[0021]FIG. 4 is a schematic plan view diagram of one embodiment of thepresent invention seaming process;

[0022]FIG. 5 is a side view of one embodiment of a shaft assembly formedin accordance with the present invention for use in the process of FIG.4;

[0023]FIG. 6 is an end view taken along line 6-6 of FIG. 5;

[0024]FIG. 7 is a cross-sectional side view taken along line 7-7 of FIG.4;

[0025]FIG. 8 is a cross-sectional side view taken along line 8-8 of FIG.4;

[0026]FIGS. 9, 10, and 11 are cross-sectional side views of oneembodiment of a seaming operation;

[0027]FIGS. 12, 13, and 14 are cross-sectional side views of anotherembodiment of a seaming operation;

[0028]FIG. 15 is a cross-sectional view of a prior art channel;

[0029]FIG. 16 is a top-down plan view of one embodiment of a unitarycover plate formed in accordance with the present invention; and

[0030]FIG. 17 is a side view of a container just prior to entering amake-up point.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0031] The present invention includes a number of unique features thatmay be used jointly in a single seaming assembly, or separately, ascircumstances warrant. One aspect is the unique use of a single shaftassembly to perform a two-step seaming operation on a single station.Referring to FIG. 4, a shaft assembly 100 includes a first roller 102and a second roller 104. The shaft assembly 100 is located radiallyoutward of its respective station, relative to the axis of rotation ofthe lifter table 60 and seaming head 62. The shaft assembly 100 isconnected to the seaming head 62 in a manner that allows the rotarymotions described below.

[0032] During use, the first roller 102 performs a first seaming stepresulting in partial closure of the joint, and the second roller 104performs a second seaming step resulting in final closure of the samejoint. As will be appreciated by those skilled in the art, because theshaft assembly is dedicated to a single station, there is no need toalter the shaft assembly 100 should the total number of stations in aseaming machine be changed. The shaft assemblies are standardized to aparticular station radius and as such are applicable to that machineregardless of the number of stations.

[0033] Referring to FIGS. 5, 6, 7, and 8, one embodiment of the shaftassembly 100 includes an upright shaft 106 having upper and lower ends108 and 110, a block 112 having opposite ends and a middle region, and acam assembly 114. The first roller 102 and second roller 104 arerotatably connected to the opposite ends of the block 112 about uprightaxes. The middle region of the block 112 is connected to the lower end108 of the upright shaft 106. During use, the block and shaft rotatetogether about the centerline of the shaft.

[0034] The cam assembly 114 includes a first cam follower 116 and asecond cam follower 118. The cam followers 116 and 118 connect to asupport member 119 that is attached to the upper end 108 of the shaft106. The support member 119 and shaft 106 rotate together about thecenterline of the shaft. During use, the cam followers 116 and 118 arelocated adjacent the seaming cam 66. The cam followers 116 and 118follow the contour of the seaming cam 66 and, in doing so, cause thesupport member 119 to pivot back and forth. This motion is transmittedthrough the shaft 106 and block 112 to result in the first and secondrollers 102 and 104 pivoting laterally in and out in a like manner.

[0035] Each cam follower is responsible for directing one of the rollersto perform its seaming step. When not performing this step, the camfollower simply responds in a complementary manner to the direction ofthe other cam follower. For example, to conduct the first step, thefirst cam follower 116 is, at first, a master cam follower and isarranged to follow the contour of the seaming cam 66 as the lifter table60 and seaming head 62 rotate about the spindle 64. The second camfollower 118 is located below the first cam follower 116 and is, atfirst, a slave cam follower, designed to complement the motions of thefirst cam follower 116 during the first step of the seaming operation.For the second step, the role of the cam followers (master and slave) isreversed. The second cam follower 118 becomes the master cam follower,while the first cam follower 116 becomes the slave cam follower. It hasbeen found that the use of the above described arrangement is a moreefficient and less expensive solution for controlling the movement ofthe shaft assembly than the box type cams which are currently used inknown single-shaft assembly systems.

[0036] The cam assembly may also include eccentric devices to facilitateseam setting procedures at the first and second rollers. Further,eccentric shafts may be used at the first and second cam followers toreduce fabrication tolerances at the cams. In FIG. 7, height adjustmentcomponents are provided to eliminate axial clearance.

[0037]FIGS. 9, 10, and 11 illustrate one embodiment of a seamingoperation in which the first and second rollers 102 and 104 press thecombined flanges 48, 50 against the chuck 80, causing the flanges todeform into a desired shape. FIGS. 12, 13, and 14 illustrate a secondembodiment of a seaming operation. The first and second rollers 102 and103 have groove shapes that include a number of rounded edges.

[0038] Referring now to FIGS. 15, 16, and 17, a unique cover feedassembly 120 is described for providing end closures 28 to the make-uppoint 30. Referring to FIG. 16, the cover feed assembly 120 includes aunitary plate 122 having a lower surface 124 and a shallow channel 126in the lower surface for holding end closures 28. Inwardly-extendingflanges 128 bound the side walls of the channel 126. The channel 126 maybe formed in the unitary plate 122 by being machined out of a solidmaterial, or alternatively, may be formed in the unitary plate 122 bybeing molded in the plate during formation.

[0039] Installing the unitary plate 122 requires only a minimal numberof fixing bolts, e.g., the embodiment shown has as few as three fastenerlocations 130. These particular positions are easy to access duringinstallation, maintenance, and cleaning. In addition, various locatingpins 132 help to correctly align and position the plate duringinstallation. Referring to FIG. 17, the particular plate 122 shown hasthe added benefit of holding a container guide 134 that can stayattached to the plate 122 while still allowing a wide range of containerheights to be handled. Since the container guide is bolted to themachine plate 122, the guide is adjusted together with the plate duringreconfigurations. In prior art configurations, a guide is mounted on anearby frame member of the machine itself and is not easily accessed.The prior art guide must be manually adjusted whenever the machine(Plateposition is altered in height in order to adjust to different containerheights. A side guide infeed conveyor 136 may also be used to aligncontainers 22.

[0040] Referring back to FIG. 16, as installed, a cover feed turret 138is located below the unitary plate 122 and adapted to rotate relative tothe unitary plate about an upright central axis 139. The turret 138includes a scalloped peripheral edge 140 and a number of push pins 142spaced along this edge at predetermined locations. During use, the pushpins 142 move the end closures 28 from one location to another withinthe shallow channel 126.

[0041] As will be appreciated from a reading of the above, the presentinvention seaming machine and process is more efficient and less costlyto manufacture than known systems. The use of a single shaft assembly ateach station allows a manufacturer to offer customers seaming machinesthat have different numbers of stations without having to redesign andseparately manufacture the shaft assembly, since the shaft assemblieswill all be based on the same pitch circle diameter at the stations.

[0042] This is not the case with the prior art configuration, sincemodifying the number of stations in a machine leads to different lengthsof seaming arms being required. Further, on their turn they have thedisadvantage that the changing seaming torque causes different angledeflections on the standard size seaming shaft, which makes the propersetting-up of the seaming station more difficult and requiring moretime. It can lead also to “side seam jump-over” and “seam bumps”. Stateddifferently, the present invention shaft assembly can be standardizedfor use with various machines. Since the same shaft assemblies can beused, the process is less costly in terms of tooling stock costs. Inaddition, using a single shaft assembly on a single container results ina simpler process and fewer setting errors.

[0043] Constant seaming arm lengths also provide for better seamcontrol, thereby allowing thinner container and cover materials. Inaddition, the settings that position the rollers relative to the blockcan be maintained in the shaft assemblies if these need to be changedover when going from one can size to the other and back.

[0044] While the preferred embodiment of the invention has beenillustrated and described, it will be appreciated that various changescan be made therein without departing from the spirit and scope of theinvention.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:
 1. A seaming machine forforming an air tight joint between a container and an end closure, themachine comprising: (a) a seaming head rotatably connected to a centralspindle, the head including multiple shaft assemblies; and (b) a liftertable located below the seaming head and including multiple stations,each station capable of receiving a container; (c) wherein during use,the lifter table and seaming head rotate in unison about the centerlineof the spindle, thereby moving a stream of containers through theseaming machine; and (d) wherein a single shaft assembly is provided ateach station to perform a two-step seaming operation on a singlecorresponding container.
 2. The machine according to claim 1, whereinthe multiple shaft assemblies are located radially outward of theirrespective station, relative to the axis of rotation of the lifter tableand seaming head.
 3. The machine according to claim 2, wherein thelifter table includes a lifter at each station and the seaming headincludes a chuck at each station; and wherein during use, each containerand end closure are held at a station between a lifter and a chuck. 4.The machine according to claim 1, further comprising a cover feedassembly for providing end closures, the cover feed assembly including aunitary plate having a lower surface, a shallow channel in the lowersurface for holding end closures, and inwardly-extending flangesbounding the side walls of the channel.
 5. The seaming machine accordingto claim 1, wherein the shaft assembly includes first and secondrollers; the first roller for performing a first seaming step resultingin partial closure of the joint and the second roller for performing asecond seaming step resulting in final forming of the joint.
 6. Themachine according to claim 5, further comprising a seaming cam, theseaming head and lifter table rotating relative to the seaming camduring use; wherein the shaft assembly includes a first and second camfollower arranged to follow the contour of the seaming cam as the liftertable and seaming head rotate about the centerline of the spindle; themotion of the first and second cam followers providing rotary input toaccomplish the two-step seaming operation of the first and secondrollers.
 7. The machine according to claim 6, wherein the first camfollower acts as a master cam follower that positions the first rollerto accomplish the first seaming step, the second cam follower being aslave to the first cam follower during the first seaming step; andwherein the second cam follower acts as a master cam follower thatpositions the second roller accomplish the second seaming step, thefirst cam follower being a slave to the second cam follower during thesecond seaming step.
 8. The machine according to claim 7, wherein theshaft assembly includes an upright shaft having upper and lower ends anda block having opposite ends and a middle region; the first and secondrollers being rotatably connected to the ends of the block about uprightaxes; the middle region of the block being connected to the lower end ofthe upright shaft; wherein during use, the block and shaft pivot jointlyin a manner corresponding to the pivotal motion of the first and secondcam followers in response to the contours of the seaming cam.
 9. Themachine according to claim 8, wherein the first and second rollers areadjustably connected to the block.
 10. The machine according to claim 8,wherein the distance between the rollers and the centerline of the shaftis adjustable.
 11. The machine according to claim 8, wherein the blockincludes an eccentric seam setting device.
 12. The machine according toclaim 8, wherein the block includes a height adjustment device.
 13. Themachine according to claim 1, further comprising a seaming cam, theseaming head and lifter table rotating relative to the seaming camduring use; wherein the shaft assembly includes a first and second camfollower arranged to follow the contour of the seaming cam as the liftertable and seaming head rotate about the centerline of the spindle;wherein, during the first seaming step, the first cam follower acts as amaster cam follower to position the shaft assembly to accomplish thefirst seaming step, the second cam follower being a slave that providesa complimentary motion to that of the first cam follower; and, duringthe second seaming step, the second cam follower acts as a master camfollower to position the shaft assembly to accomplish the second seamingstep, the first cam follower being a slave that provides a complimentarymotion to that of the second cam follower.
 14. The machine according toclaim 13, wherein the shaft assembly includes first and second rollers;the first roller for performing a first seaming step resulting inpartial closure of the joint and the second roller for performing asecond seaming step resulting in final forming of the joint.
 15. Themachine according to claim 14, wherein the multiple shaft assemblies arelocated radially outward of their respective station, relative to theaxis of rotation of the lifter table and seaming head.
 16. The machineaccording to claim 14, wherein the lifter table includes a lifter ateach station and the seaming head includes a chuck at each station;during use, each container and end closure being held at a stationbetween a lifter and a chuck; the corresponding shaft assemblies beinglocated radially outward of their respective station, relative to thecentral axis.
 17. The machine according to claim 14, wherein the shaftassembly further includes an upright shaft having upper and lower endsand a block having opposite ends and a middle region; the first andsecond rollers being rotatably connected to the ends of the block aboutupright axes; the middle region of the block being connected to thelower end of the upright shaft; wherein during use, the block and shaftpivot jointly in a manner corresponding to the pivotal motion of thefirst and second cam followers in response to the contours of theseaming cam.
 18. The machine according to claim 13, further comprising acover feed assembly for providing end closures to a seaming machine, thecover feed assembly including a unitary plate having a lower surface, ashallow channel in the lower surface for holding end closures, andinwardly-extending flanges bounding the side walls of the channel. 19.In a process for affixing an end closure to a container opening, thecontainer being located at a processing station in a container closingmachine; the process including a seaming operation to form an air tightjoint between the end closure and the container; an improvementcomprising: using a shaft assembly adjacent to each processing stationto perform a seaming operation on a single container during use; whereinthe shaft assembly includes first and second rollers; the first rollerfor performing a first seaming step resulting in partial closure of thejoint and the second roller for performing a second seaming stepresulting in final forming of the same joint.
 20. The improvementaccording to claim 19, wherein the shaft assembly further includes anupright shaft having upper and lower ends, a block having opposite endsand a middle region, and a cam assembly; the first and second rollersbeing rotatably connected to the opposite ends of the block aboutupright axes; the middle region of the block being connected to thelower end of the upright shaft; the cam assembly causing pivoting of theblock relative to the centerline of the shaft; and wherein, during use,the cam assembly positions the block to enable the first roller toconduct the first seaming step and, once completed, pivots the block toenable the second roller to conduct the second seaming step.
 21. Theimprovement according to claim 20, wherein the seaming operationincludes using a seaming cam and wherein each shaft assembly includesfirst and second cam followers located at the upper end of the shaft andin contact with the seaming cam, the cam followers adapted to transmitpivotal motion to the block to position the first and second rollersduring use.
 22. The improvement according to claim 21, wherein duringthe first seaming step the first cam is a master cam and the second camis a slave cam, and during the second seaming step the roles arereversed.
 23. The improvement according to claim 19, further comprisinga cover feed assembly for providing end closures to a seaming machine,the cover feed assembly including a unitary plate having a lowersurface, a shallow channel in the lower surface for holding endclosures, and inwardly-extending flanges bounding the side walls of thechannel.
 24. A cover feed assembly for providing end closures to aseaming machine, the cover feed assembly comprising a unitary platehaving a lower surface, a shallow channel in the lower surface forholding end closures, and inwardly-extending flanges bounding the sidewalls of the channel.
 25. The cover feed assembly according to claim 24,wherein the channel is formed in the unitary plate by being machined outof a solid material.
 26. The cover feed assembly according to claim 24,wherein the channel is formed in the unitary plate by being molded intothe plate during formation.
 27. The cover feed assembly according toclaim 24, further comprising a cover feed turret located below theunitary plate and adapted to rotate relative to the unitary plate aboutan upright axis, the turret including a peripheral edge and a number ofpush pins spaced along the periphery at predetermined locations; whereinduring use, the pins move end closures from one location to anotherwithin the channel.